If you've been blue over an autumn without Sipowicz and Sorenson, you'll be happy to know that "NYPD Blue" returns tonight -- with Internal Affairs squeezing the detectives' shoes, some signature bare butts and an attempt to wrap up months-old story lines. Tonight's episode opens with a helpful but too-brief "Previously on 'NYPD Blue' ..."

We've done a lot of channel surfing since May, so where exactly did things stand back then in the 15th Precinct?

"NYPD Blue"

When: Tonight at 10 on ABC.

Starring: Dennis Franz, Rick Schroder and Kim Delaney.

Detective Jill Kirkendall was grappling with her slimeball ex-husband Don -- in cahoots with a dirty cop named Harry Denby -- while the life of Andy Sipowicz (Dennis Franz) continued to resemble that of Job. His son, Theo, had been hospitalized with possible leukemia.

Now, six months have passed and, in five days, Theo is expected to undergo yet another blood test that either will give him a clean bill of health or pronounce him seriously ill. Sipowicz, working a triple homicide case, is ready to jump out of his skin.

Danny Sorenson (Rick Schroder) is still seeing fellow cop Mary Franco (Sheeri Rappaport) although they haven't been spending much time together. That clearly bothers her but he doesn't really seem to mind. Relationships have never been his strength and, as we've seen in the past, he has a hard time getting close to anyone. However, Sorenson is almost flirtatious with widowed cop Diane Russell (Kim Delaney) although the two agree that it's best if they stay friends and colleagues and nothing more.

As the squad room simmers with personal concerns and the murder case, the cops are dealing with the "rat squad." The detectives have "lawyered up," because IAB is suggesting they're a dirty squad that was trafficking in drugs with Kirkendall and her ex-husband, who is now in Rikers Island prison. Andrea Thompson, the blonde who portrayed divorced mother Kirkendall, left the series to try her luck as an Albuquerque news reporter and is nowhere to be found.

I'm happy to report that in the second episode, the IAB story line and the one concerning Theo are wrapped up, allowing the show to begin exploring other plot strands.

ABC sent critics the first two episodes with a plea that they not reveal a particular plot twist "in any way, shape or form." If you're at all alert, you'll see it coming.

As for the fate of Theo, let's just say that Andy is seen whistling, smiling and cracking jokes in next week's episode. If the writers had condemned Theo to chemotherapy or death, I think I might have permanently switched over to CBS's "Judging Amy." Too often, writers (such as those on another favorite, "ER") confuse unrelenting tragedy with great drama. In small doses, yes; in large waves, no. That can prove exhausting to viewers.

It's hard to judge a season, especially an eighth, on two episodes. Plots past hang heavily, like ankle weights, around the cast. And some of the personal interactions -- a tender scene between Sipowicz and his son, the secret twist -- are more interesting than the police work.

The biggest challenge facing "Blue" will be writing out a couple of key characters. Actor James McDaniel, who plays Lt. Arthur Fancy, will be gone after 13 episodes. His wife and children, shown early on, have long vanished. Delaney will leave after this season to star as a criminal defense attorney in a new Steven Bochco drama set in Philadelphia.

"Blue" is renewed through the 2001-'02 season which means it needs to start introducing new characters and laying the groundwork for the future. It rebounded from the loss of David Caruso and, amazingly enough, Jimmy Smits.

"Blue" smartly added Henry Simmons as Detective Baldwin Jones and returned Bill Brochtrup as police administrative aide John Irvin. It's turned the character of Greg Medavoy, played by Emmy winner Gordon Clapp, into something of a buffoon.

The ABC series doesn't need to reinvent itself, just import a couple of new players (especially women), keep a couple of old ones and try to be as topical as possible. The cop drama is no ground-breaker like "Once and Again," which held its time slot in the fall, but its service record is stellar.